On April 20, 1819 he arrived in the city of Angostura,
from Apure, bearing important dispatches and news of the victory of
the Republicans on April 2 in the action of the Queseras del Medios.
At that time, Demarquet was aide de camp of the Liberator and
obtained the post of captain of cavalry. The news, brought by an
envoy from Bolivar, was celebrated at Angostura by the ringing of
bells and salvos of artillery.

This began a steady progression of
promotions, the next two years later:

On 15 June 1821, by the general order issued in San
Carlos, the Liberator named him Deputy to the General Staff and, with
this position, we see him at the final battle of the liberation of
Venezuela.

Barrios

The “final battle” was the
battle of Carabobo, on June 24, 1821, celebrated in Venezuala today
as Battle of Carabobo Day or "Army Day”.

Of the countless battles won by Bolivar in the course of
liberating the Spanish colonies in the South American continent,
perhaps Carabobo was the most important.

For, if each of these victories was the result of the
Liberator's superior military genius, and if at Boyacá the
elements of his triumph in crossing the Andes were audacity,
surprise and improvisation, offsetting the patriot army's
almost complete lack of food supplies, military equipment and
adequate clothing, at Carabobo these three important factors
prevailed: foresight, organization and military strategy
superior to that of the enemy.

To these three factors could be added another, without
which success might not have been attained-luck. For it is a proven
fact that to achieve success in any human activity, including
business as well as games of chance, such as cards, there is
requisite, over and above the factor of knowledge, another
indispensable ingredient-luck!

The combination of these two elements was decisive for
Bolivar. Thus, at Carabobo, preparedness, audacity and superb
strategy, together with this last ingredient, fortune, resulted
in his smashing victory.

Carabobo was the climactic battle in which this colossus,
operating in a territory ravaged by ten years of bloody warfare,
where one-third of the populace had been annihilated, and totally
lacking the resources to provide even the essentials for subsistence,
he created, in less than two years (the period between Boyacá
and Carabobo) an army capable of destroying the military strength of
the royalist armies in Venezuela, then considered the most powerful
fighting forces in all of Spanish America, from Mexico to Patagonia.

Del Rio talks at some length about
how organization and careful planning helped Bolivar triumph here. It
is very likely at this point that Demarquet played, as he would
later, a key role in such unglamorous but essential efforts. However,
his specific role is little documented. Even the Venezuelan document
cited above says little about his part in this battle, even as it
lists him among “The Heroes of Carabobo”.

By 1822, he was enough of a key
player to be implicated in internal struggles. Odriozola
names him as, in effect, one of several flunkies helping to spread
malicious rumors in May of that year:

The forge of the hostile rumors which spread against the
division was in the offices of General Torres and Florès and
their satellites, the Colonels Pedro Marueitio, Vicente Gonzalez,
Leon Cordero and Demarquet. However they could they were bent on
attributing to the division improper or even quite hostile views.

The little respect and great ill
feeling implied in such a remark gives a hint of what Boussingault
meant when he said “he suffered much in the milieu in which
circumstances obliged him to live“. As he took unpopular
actions on behalf of more powerful figures, Demarquet may often have found
himself the target of similar comments. But Bolivar's regard for him
only grew.

One evidence of this is that he was one
of the few people present at the Guayaquil Conference, an important, if slightly mysterious,
meeting between Bolivar and San
Martin:

Simón Bolívar, Venezuelan, and José
de San Martín, Argentinian, met at Guayaquil, Ecuador, on July
26 and 27, 1822. Since then discussion has been rife in the Latin
American press and in historical publications as to what actually
took place at these meetings, where the two Liberators conferred in
private-with no witnesses to their talks. However, much substantive
information can be derived from three documents written immediately
after the second meeting and dated July 29, 1822. Two of these are
official communications from Bolívar's Chief Secretary, to the
Colombian Government in Bogotá, and to General Sucre in Quito,
giving a detailed account of the discussions; the third is a personal
letter addressed by Bolívar to General Santander, Acting
President of Colombia during Bolívar's absence. This letter
confirms the statements of the two official communications.

Lara cites Demarquet's presence
there: “Demarquet, who would later be one of Bolivar's
aides-de-camp and a man who had all his trust, as that of marshal
Sucre, the secretary general of San Martin, the Frenchman Soyez
accompanied [Bolivar] in the meeting. These two officials, Demarquet
and Soyez, would give firsthand information on the historic interview
to their young compatriot, author of the Letter of Lafon.”A.
Darío Lara,La
vitrina de un país sobre el mundo This is an error for “Lafond”, who, in his own work, says that he obtained the details from "Bolivar's aide-de-camp, who served him as secretary on this occasion".

Another promotion came that year:

In August 1822, Bolivar appointed him Adjutant General of
the General Staff. Both were in Guayaquil.

Barrios

Yet, for unknown reasons, Demarquet,
however briefly, retired, as per a note from December 1822:
“22--Ibarra_ Bolivar orders the Intendente Aguirre to pay 100
pesos to the retired Lieutenant Colonel don Carlos Eloy Demarquet on
account for back wages.” Boletin
de la Academia Nacional de Historia,
VOl. XVIII, January-June 1924, 195. (It was probably
on this occasion that he gave a hint of his literary culture:
“Demarquet added a verse from his compatriot Racine - D'autres
temps, d'autres soins... - when he wanted to express his
sentiments in having been obliged to momentarily separate himself
from service” Vila,
97.)

This “separation” did not
last long. Barrios says that in February1823, Demarquet was made a
lieutenant colonel of cavalry in February of that year. Barrios.
(According
to the note above, he was already a lieutenant colonel when he
retired, so he may simply have returned to service at this rank.)

In the same year, he went to Quito,
probably for the first time. Laffite-Carles
His engagement that same year at once sealed his bond with that
city. Bolivar too was cementing his local bonds. An Ecuadorian writer
says that the battle that took place at this time was central to
Bolivar's relationship with that country. Finally, the bond between
the two men too became stronger, even a matter of course; in the
correspondence of this period, Demarquet already begins to appear as
the Liberator's intermediary:

Of the key tasks we discussed in the previous lines, the
first, the strengthening of our independence with the subjugation of
the rebel Pasto, the Liberator, personally, would achieve in the
bloody battle of Ibarra of July 17, 1823 against the armies of the
warlords Mercanchano and Agualongo, who had gone far ahead to within
about twenty miles of the capital, threatening the city of Quito,
still young in its life of freedom. The battle of Ibarra or Tahua
Bridge, is important for the Ecuador-Bolivar relationship, because
there, for the first time, the lancers of Quito shone in the
regiments of Granaderos and Guías, under the direct command of
the Liberator himself. It is also in our country the only armed
action in which Bolivar personally was involved....

The response of Ecuador to Bolivar's call was formidable,
all without exception, rich and poor, young and old, noblemen and
commoners applied to take up arms and to train in their use. The
Liberator's recognition of this patriotic response to his call for
militias was recorded in his famous proclamation of 28 June 1823....

On July 17 at 2 pm, at the very doors of Ibarra, Bolivar
ordered the attack and it was carried out with so much skill and
speed, that in a moment the enemy was completely defeated and
dispersed, despite its fierce resistance. Eight hundred bodies were
left on the adversaries' field.

Colonel Demarquet, Bolívar's aide, includes the
following paragraph in the account of the battle he sent to the
Secretary of War and Navy of the Great Colombia: "I just want to
express to you the satisfaction H. E. had in seeing the prodigies of
valor done by the cavalry, and the admirable patriotism shown by this
people helping the troops by every means possible, leaving the enemy
in perfect ignorance of our movements, capturing the defeated, and
finally collecting all the weapons and the spoils that those wretches
left in their hasty flight.”

This is only one of numerous
communications signed by Demarquet at this time:

On 18 July 1823, he signs an official letter from Bolivar
for the Brigadier General Bartolomé Salom, by which orders
Salom continued to command the Republican army and was directed to
Pasto to pacify it.

Barrios

It was during the “pacification”
of Pasto that Demarquet is said to have wept over a harsh sentence.
He may have hardened himself, however, to other sufferings. By some
accounts, this campaign was particularly brutal. Rufino says that the
local population bitterly resisted and was as bitterly repressed:

Salom and his successors Florès and Obando met the
watchword in great cruelty...

Persecution was the order: thus, the Acting Secretary of
Bolivar, C. E. Demarquet, ordered Colonel Heres from Tacambuco, 16
July 1823, to apprehend Francisco Aguirre by all possible means, and
that if present, he would be sent to Spain, and if not, to
authorize any citizen to take his life or betray him to be shot, and
added that if he was not found all his assets would be confiscated
and his family sent to Quito.

He also quotes a later letter from
Bolivar to Santander on October 21, 1825:

The Pasto must be destroyed, their women and children
transported to another area, making that region a military colony.
Otherwise Colombia will remind the people of Pasto when there is the
least uprising or disturbance be it in a hundred years, they will
never forget our ravages, only too well deserved.

As described by Rufino, at least, this
campaign against a local insurgency recalls the French
Revolutionaries' repression of the Vendée
or even the harsher measures taken by American troops against supporters of the Viet Cong.

Whatever Demarquet's feelings about
specific measures, however, he was first and foremost Bolivar's loyal
aide and his overriding concern was to see that the Liberator's
objective was attained. At this point, he played a central part in
accomplishing that. During the whole period from July to the start of
August 1823, Demarquet signed a flurry of orders, circulars, etc.;
read in sequence today these suggest a long email thread. They are
addressed to officers, judges, generals, intendentes, etc. and show
Demarquet as the efficient aide keeping a tight watch on his boss'
business:

To the Intendente of Panama

H. E. asks for the war munitions which were being sent to
Guayaquil, and also asks Y. E. for a thousand rifles in addition to
those intended for the defense of the Isthmus, always those in
surplus in the State warehouses or in the hands of the country's
militias, since H. E. does not want under any pretext to take them
out of the hands of the veteran troops of this garrison. H. E.
commands me to tell you that he expects the strictest execution of
this order, because circumstances demand it, being poorer every day,
all the veteran troops having marched for Peru with all the arms
which were on the Colombian coast.

C. E. Demarquet

Quito, June 27, 1823

To the Commander of the Warship "Guayaquilena",
Lieutenant Colonel Carlos Wright.

Foul Pasto has again risen up since having had some
success against Colonel Florès. As a result H. E. has headed
for this city by post, leaving as a rear guard his General Staff and
Secretariat and has put me in charge of it for the time being.

H. E. order that as soon as you receive this order you
gather and land the troops commanded by Colonel Carvajal, in the port
of Barbacoas, in that that of Esmeraldas, choosing that which is
closest. Once you have executed this landing continue with the
attached packet and without losing time for the port of Panama in
order to receive there rifles and ammunition which you will take with
the same dispatch to Guayaquil for the use of the Intendente of that
Department.

... Quito Headquarters, June 27, 1823.--

C. E. Demarquet

.....

To the Political Magistrate of the Department of Ibarra.

H. E. the Liberator President, aware of the great
urgencies of State to maintain the army working against Pasto, and in
which this canton is presently the most interested by the approach of
the enemy, has wanted to send to require a four thousand peso
donation to this neighborhood, for the execution of which he has
commissioned Y. This quantity must be distributed between the
powerful people or those known to be disaffected, to those who point
them out the double or the triple with respect to those who are not.
Understand by disaffected those who have relations with the Spanish
government, by their families, by their employment or by persecutions
by the patriotic Government...

...Otavalo, July 8, 1823

C. E. Demarquet

To General Bartolome Salom.

I have the honor of sharing with Y. that H. E. the
Liberator has seen your messages from yesterday, and orders me to
answer you as a result, that he thanks Y. for your good behavior in
service, but lets you know at the same time he will in no way
compromise your part, since he already know your views. It was not
without disgrace that the enemy, knowing the small number of Herran's
party, ambushed some of them or surprised them and destroyed them.
You must have him present himself and warn him how much he will lose
by taking risks and giving the enemy advantages in the only system of
war that he knows, and that to the contrary he will win by not risking
a single of our soldiers, succeeding also in keeping the pastusos
under the illusion that he fears them....

... Otabalo, June 8, 1823

C. E. Demarquet

Etc. For this period, pages and pages
of these appear, most couched quite clearly as the Liberator's
wishes O'Leary.

Paradoxically, these serve to
illustrate why Demarquet's role has been less known that it might
have: often, his voice was indistinguishable from the Liberator's. It
is clear in most of this writing that, whoever decided the action
being ordered, the order was to be regarded as coming from Bolivar
himself. How true this was in practice is probably lost in the
intimacy of their collaboration. But anyone who has worked in an
organization of any size has witnessed the phenomenon of a leader not
only speaking through a close aide, but delegating many daily
decisions to that person. This may have been all the more true of
Bolivar, who "admitted to having the habit of signing his
letters without examining them and of dictating several
simultaneously: I signed the letter without reading, as I did quite
frequently when I was in a hurry." José
Luis Salcedo Bastardo, Un
Continente y un Destinon50

It was sometime in this year that
Demarquet met his wife and in this year or the next that he married
her. His first two sons were probably born around this time and money
was no doubt a concern. This may have inspired his first steps into
business: "Demarquet formed a commercial company with Mariano
Maldonado and on November 24, 1824 they signed a document by which
the Frenchman gave him 5000 pesos 'to buy merchandise in
Jamaica' " Fernando
Jurado Noboa, Un
soldado de Bolívar en Ambato: Ignacio Holguín Sánchez.
He had probably retired from service again by then; he was certainly
retired by 1825 when the House of Representatives in Bogotá
“denied a request made by him to receive his back wages, for
not having 'checked them properly' ”, and another effort by him
in the same sense was also given a negative response. We suppose the
then lieutenant colonel Demarquet did not meet the requirements of
law for that kind of recognition.” Sergio
Elías
Ortiz, Franceses
en la independencia de la Gran Colombia,
Bogotá, 1971, 189-190.

Perhaps at this point Bolivar stepped
in? One source says that in December 1825, Demarquet was the governor
of Otavalo colonyia.blogspot.com
. If so however, nothing of note seems to have marked
his time there. Returning to Bogotá, he tried unsuccessfully
to join the House of Representatives.

In the year of 1826, he rejoined the army in Lima, still
in the general staff and in more favor with the Liberator, who made
him his “ad interim clerk'“ In that year he was
sent on a mission to Quito as a good fixer of the differences between
the politicians.

Ortiz

On June 1 of 1826, Bolivar wrote Fernando
Penalver, an early collaborator in his struggle, from Lima.
Bolivar added at the end: “Demarquet kisses you.” Such a
salutation between Latin males is common enough. But for Demarquet,
whose correspondence tends to be formal, this was very unusual. It
seems to imply that he was particularly close to Penalver, even if no
other mention confirms this. At any rate, he was now again at the
Liberator's side.